Pseudo-Nambu-Goldstone inflation with twin waterfalls

TL;DR

This paper introduces a new inflation model where twin waterfall fields trigger the end of inflation, protected by a $Z_2$ symmetry, with a detailed reheating mechanism and a microscopic dark QCD-based realization.

Contribution

It presents a novel pseudo-Nambu-Goldstone inflation model with twin waterfall fields and a $Z_2$ symmetry, providing a natural exit mechanism and a microscopic dark QCD framework.

Findings

Successful inflation with natural parameters and initial conditions

Reheating via perturbative decay of waterfall fields through a Higgs portal

A microscopic dark QCD model for inflaton coupling

Abstract

We propose a pseudo-Nambu-Goldstone inflation where twin waterfall fields coupled to the inflaton are responsible for the graceful exit from inflation by a waterfall transition. In this scenario, the $Z_2$ symmetry for the waterfall fields and the inflaton protects the inflaton potential against dangerous quantum corrections coming from the waterfall couplings. We show that there is a wide range of natural model parameters and initial conditions for a successful inflation and discuss the reheating process by the perturbative decay of the waterfall field with a $Z_2$ invariant Higgs portal. We also present a microscopic model for the inflaton couplings to the twin waterfall fields in the context of a dark QCD with light and heavy quarks.